Worth The Wait
by Ianuaria
Summary: Sixty day sex bet, fulfilled. That's all I'm going to say. Pure Maddison. If you like it,I'll continue.
1. You Bet Your Ass I Am

_**I'm supposed to be studying, so obviously I did this.**_

* * *

"9:37 pm." he whispers against her neck as he deposits a cup of coffee beside her chart.

"What?" she gasps,nearly knocking over his offering as his breath stirs her hair.

"At 9:37 pm tonight, the sixty days will be over .Meet me in the lobby at eight; I'll even take you out to dinner first."

* * *

Eleven hours.

Eleven hours until its just them, locked in a room for a record breaking, earth shattering, mind-blowing...

She slumps against the scrub sink with a sigh.

She'd never let him get around to describing that part.

She clears out early and spends far too long agonising over a dress,heels ... underwear, before she wanders down to the hotel lobby fifteen minutes late.

She'd rather not be wearing anything at all, but she's humoring him.

"Looking good, Red." His eyes are fixed shamelessly on her dipping neckline.

She smirks because that's why she chose it.

"You don't look too bad yourself."

"You know,we _could_ go straight to the hotel." she purrs in the way she knows drives him wild.

"No way."he smirks. "I don't want you fainting on me in the middle of what I have planned."

 _Oh my._

* * *

Dinner is exquisite torture, watching her delicately lick the sauce off a shrimp, and he slips a hand onto her thigh below the table.

She pulls away.

"9:37 pm." she reminds him.

 _Two can play that game,baby._

* * *

You're back at the hotel by 9: 30 .

" Seven minutes." he grins lasciviously.

She swipes the key card to his room and smirks as she steps inside.

"You're not coming?"

"Not right now." he says, leaning comfortably against the doorframe,and she can't tell if he meant the double entendre or not.

* * *

"Five minutes." he calls through the door she's slammed in his face.

You're doing it right, this time.

"Four."

"Come on already!" she yells,and he chuckles in amusement.

"I didn't mean to be so...exact. I meant sixty days." she complains .

"It's not sixty days yet. It's only fifty nine days, twenty three hours, and fifty seven minutes."

"Fifty eight ." she snarls on the other side.

"Frustrated, are we?"

"You aren't?" she counters, and he can hear her sliding to the floor on the other side.

"You're worth the wait, remember? You bet your ass on it. I'm taking you up on that, you know."

He can hear her swallow through the door and it takes a lot not to laugh out loud.

"Fifty nine."she singsongs.

He gets up off the hall carpet and gets in position,sliding his hand into his pocket.

"Forty seconds." she growls,and he wants to knock down the door but he manages to restrain himself.

"Thirty ." he growls back,and imagines the look on her face when she sees him on the hall floor .

"Twenty." she whispers.

His fingers close around it in his pocket , rock hard and exactly what she wants.

"Ten." she giggles,turning the lock.

He tightens his grip.

"Nine. Eight, seven , six , five , four, ..." he trails off at four and lets her continue .

"Three, two, one." she flings the door open.

"Oh my _god_ , Mark!"

"Marry me?" he grins, holding out the ring .

Four carat, princess cut, rock hard, exactly what she wants.

* * *

 _ **Review, pretty please !**_

 _ **Should I continue or leave it a one shot?**_


	2. Risqué Rules

**Thank you thank you thank you for your reviews!**

 **So, I'm continuing this - no idea how long it'll be , but I'm a sucker for mutichaptered fics, but lemme know what you want in the reviews.**

 **Also, for the sake of clarity,this is set a few weeks after the failed Burktina wedding. MerDer broke up after that , so that bit is canon.**

 **I kept Burke in the fic because he's awesome,so that and clearly the whole Maddison situation is AU.**

 **Enjoy!**

* * *

 _We made it_ is her first thought as she stretches awake , bathed in the beginnings of dawn and Mark's eyes searing into hers.

"Morning." he bends his head to kiss her , and she's grateful for the gentleness of it,because her lips are still bruised from last night.

 _Last night..._ Hazy,at best. He always has this effect on her.

She rolls onto her back , assessing.

He stays propped on an arm, waiting.

The room is a tumbled mess,last night's carefully chosen seductress outfit- _not that it was necessary-_ is in the foyer and his clothes are nowhere to be seen.

The only thing touching her still-tingling skin are the sinfully soft sheets.

And the ring.

 _The ring?_

"Yeah, I slipped it on you at some point."he says,almost apologetically.

She raises her hand silently , the stone catching the soft early light and scattering rainbow droplets over his bare chest.

"Addie. Say something." he looks almost panicked .

 _ **...**_

 _Three, two...one. Oh my **god** ,Mark!"_

 _"Marry me?"_

 ** _..._**

She mostly just remembers her back slamming into the door after that,his hands all over her and his mouth crushing hers.

" _Addie._ "

"Mark?"

"Yeah, baby?"

"What the hell?"

"It's ... a ring. A damn expensive one,but only the best for you."

"Why is it a ring."

* * *

 _"Why is it a ring."_

"Feeling existential?" he attempts to distract her with wry humor.

It's either that or sex, and he never thought he'd say it but he's actually exhausted.

" _Mark._ " she snaps.

"We agreed to try, remember?"

"Try the couple thing! Dating instead of booty calls, that sort of thing."

"Well,we already did the dating thing, and the living together thing, and so this was the next step." he says, running a placating hand down her side.

He slid the ring on her finger somewhere between that first ,delicious round up against the door and the third time in the shower.

"I don't remember saying..."

"Yes? Well, I took the liberty of interpreting you jumping my bones as a yes."

"I did not jump your bones."she says indignantly.

"Evidence to the contrary,milady." he turns slightly to reveal the red marks down his back.

She has the grace to blush." Sorry."

"Don't be." he smirks. " I paid you back already."

She tears the sheets away from her body,knowing all too well his usual tricks.

"Mark Sloan, you dog."she groans,already trying to find ways to hide the strategically placed bitemarks.

"I like to _mark_ what's mine." he grins into the skin of her back.

She groans at the intended pun. "Did I sign up for a lifetime of this?"

His heart soars embarrassingly high." Does that mean..."

" _Yes_ , idiot."she laughs,pouncing and pushing him into the mountain of pillows." _Yes._ "

 **XXXX**

A few hours later, he's pouring coffee as she emerges freshly showered and terrified.

 _Here we go._

They've alternated , so far,between celebrating their engagement - he grins sappily at the word- and him soothing her irrational -well,they seem irrational to him, she clearly thinks they hold water- fears.

"Coffee?"

"Yes please." she sips gratefully, and he can't stop staring at reddened lips against the rim of the china cup.

 _A lifetime of this... sign me up._

"It's not ... too soon , is it?" she broaches the topic again.

"We waited sixty days."

"To _date_.Not get engaged." she splits hairs.

"Well,who's going to care?" he scoffs, although he can write a list as long as his arm about who will.

"Der-"

"Non-issue." he glares at her.

"But-"

"Addie, he _left_ you . Before the affair. Emotionally, he left you a long time ago. And don't make his excuses for him, because I was there, remember? Picking up the pieces."

"Mark,I won't deny you helped me through the worst months of my life... and I love you.I realise that, now. I love you. I'm just not sure of I can ... get into something so _committe_ _d,_ so soon.

And Derek,he'll be-"

 _Mad as hell_ he thinks , satisfied.

For years, he watched the love of his life with his best friend, for years he chanted _shalt not covet_ even though he hasn't set foot in church since he was sixteen.

And now she's all his.

"He'll be back with Meredith at some point." he supplies instead, pushing a plate of fruit towards her.

She nibbles distractedly - _how is she not ravenous after last night? -_ and stares out the window at gathering rain clouds.

He admires the ring on her finger, medieval possessive pride swelling within him.

"It won't be unseemly?Marrying the dirty mistress two months after getting divorced?" she arches an eyebrow and he knows she's teasing.

"Who said we have to get married right away?" he sets her coffee cup on the table and nuzzle her neck.

"No?" she attempts to breathe steadily.

"We'll have a long engagement." he murmurs. "We've already figured out its worth the wait."

"Mm." she exhales.

And pushes him away.

"Hey!"

"There need to be rules."she says pensively.

 _Dear god._

"Can we do this after I finish having hot sex with my fiancée?"

She smiles slightly at the title."No."

"Shoot,then." he pulls away from her and refills his cup.

She seizes a linen napkin from the room service cart and a pen from the bedside table.

"No one walks out."she says softly,biting her lip, and he feels a surge of protectiveness . "No one stops talking, no one sleeps on the couch and no one walks out."

"Done."he says,reaching for the pen.

 _1\. Always: talk, share,listen._ _Never: sleep on couch,ignore calls, walk_ _out._

"Now you go."she says, mood marginally lifted; she starts in on a piece of toast.

"No secrets." he stares into her cyan eyes."Transparency."

"Only if it doesn't hurt someone." she says.

"Someone _else_.Between us, total honesty. We've lost too much time already, time when we could've been together, to waste more trying to figure out cryptic shit." he says bluntly,and she acquiesces.

 _2\. Always be honest,unless it's someone else's dirty secret._

"You could be slightly more eloquent." she suggests,barest hint of a smile curving coral lips.

He kisses them, and the plot gets lost for a second.

"We're not done yet ." she reminds him primly.

" turn."

"I'm always right."

"Huh?"

"I'm always right."

"No freaking way."

"I'm right until proven otherwise." she compromises, and he relents because the past has proven that this is usually the case.

 _3\. Addison is right unless proven otherwise. If wrong,debts will be paid in sexual favors._

"I don't remember that last bit."she peers at the napkin.

"I added it."he grins, waggling an eyebrow."Come on,live a little."

"Repayment better go both ways." she warns.

"Of turn now... hmm. Date ."

"Yes please."

 _4\. Date night every week at restaurant of alternate party's choosing._

"With the formal wording,and everything."she rolls her eyes.

"It's binding."

"Okay, my turn,so... no inappropriate hospital sex."

"No fair!"

"We're not horny interns anymore."

"Sometimes?"

"Well..."

"You know you wanna."

"Fine. _Sometimes_." she reaches for the pen and writes this one herself.

 _5\. Hospital sex only when deemed appropriate by both parties and not in linen closets or exam rooms._

He kisses the top of her head at the mention of exam rooms.

She's still wounded, and he's determined to heal her.

"Your turn." she smiles.

He's not sure how to bring it up, given their history .

" Addie... will there be another onesie?"

She freezes on her way to the cookies. "Mark..."

"When...whenever or _if_ ever you're ready. And you want to,really really want to, I'd like a baby."

"Still? After everything , you still want a baby? With me?" she says,tears welling.

"Adds, did me flying here on the world's longest lasting transcontinental booty call not prove my dedication?"

She laughs shakily." I love you."

A thrill runs up his spine at the breathy words."Likewise."

"Plus, we'd make gorgeous kids." he grins, and she gives him a real laugh and writes it on the napkin that maps their life together.

 _6\. Kid._

He reclaims the pen.

 _6\. Kids._

She makes a skeptical face but doesn't argue.

"Is that it?" she queries.

"It is for ?"

"I've pretty much got everything I want." she smiles slowly.

"Come here, fiancée. God, I love that word."

"Wait."

He flops against his cushions with a groan.

 _7\. Either party reserves the right to create a new rule. Approval of the other party is necessary._

" _Now_ I'm done." she says,sinking into his lap.

 **XXXX**

"Addison Sloan?"

"Really?" she wrinkles her nose.

"You hyphenated with him." he says,slightly churlish.

"Addison Forbes Montgomery-Sloan. I ... I like it."she grins shyly.

"Me too."

 _It sounds so right._

He pinches himself under the covers.

This is all he's ever wanted, the right to spend hours lazing around in bed with her,hold her while she sleeps, wake up to her kisses and everything in between,the crazy bitchy tantrums and the brilliance of her surgeon's mind,disastrous cooking attempts and drunken 2 am ranting.

He'll be here though it all, and rightfully, not as the husband's guilty covetous best friend.

"When do we tell everyone?" she muses.

"That ring... doesn't exactly hide itself."

"I could take it off."

"No can do." he says easily.

"Mark..."

"Addison..."

"Derek will flip."

"We'll tell him before everyone else." he'd thought of this days ago, and no matter what went down this past year,the man is his best friend.

He deserves at least a heads up.

Although he _is_ going to enjoy watching the fool squirm.

Which he will.

"Promise?" she props herself up on her elbows, crimson hair brushing the cream sheets.

"Bright and early tomorrow morning."

" Ew. We have to go to work tomorrow." she shudders, snuggling against him."I want to stay here."

He kisses her forehead."We have forever,baby."

 **XXXX**

"Time for the last-ever walk of shame." she says, pulling day before yesterday night's dress over her head.

"Down the hall."

"Still a walk of shame. But I won't be doing them from now on." she smiles, leaning in for a goodbye kiss .

She returns to the car in a black sweater that flops gracefully over her hands, and he rolls his eyes and her sleeves.

"You're ruining my outfit."she mumbles,shaking them back down.

"Why don't you want anyone to _know_?" he snaps, wishing she'd just decide for once.

 _In or out, yes or no._

" It's not like that, Mark, just...Derek first,okay? We owe him that."

"Guess we do." he says glumly, starting the car.

 _How does one do this, exactly?_ _Hey,Former and Possibly Ex Best Friend, I, your wife stealing best friend,am engaged to said Ex Wife before the ink has dried on your divorce papers?_

Addison can hold the mirror this time while he sutures his face.

" It's raining." she leans up to put on her lipstick in the rearview mirror.

"When isn't it in this hellhole?"

 **XXXX**

"He's not here."she announces, having made a full circuit around the trailer.

"Where else is he going to be? He broke it off with Grey, remember? Or maye the other way around."

"I... oh, look, there he is."

He turns to see his foster brother trudging towards them, sweaty after an early morning run, staring curiously at the car parked beside his.

"Hey Addie." he says, almost cheerfully, the smile dropping off his face the minute he sees him standing a few feet behind her.

"Why are you two here? You're kind of making me nervous." he asks, sitting down in the deck.

"You're... being nice to me." Addison says, stunned.

"Yeah,well- we were friends first. All three of us. And losing Meredith, Preston walking out... it just made me realise that no matter what I don't want to lose my best friends." he rests an arm on her shoulders, looking into her eyes the way he used to in med school. " It's hard to forget the way we we're, Addie,and I'm sorry we hurt each other. But if you'd give me a second chance, if you'll trust me again ... I want to make it _work_."

 **XXXX**

He can feel his teeth grinding involuntarily as Derek drapes an arm over his ex wife's shoulders - probably more habit than anything else - and he's seen them do much worse over the years ,but now it's different.

It's his ring on her finger now, he isn't the one who treated her like crap, forcing her to uproot her life and fly across the country for him only to watch each agonising second as he pined after his intern.

Derek has no right, but before he can open his mouth,Addison shifts furiously from under her ex husbands arm and stands in front of him.

He frowns." What's the matter,Addie?"

"The _matter_ , Derek? The matter is that you just think I'll always be here,for you come crawlin back to , when your girlfriend kicks you out.

I gave up _everything_ for you, Derek, my practice, my friends, my family in New York, everything, just to make it work with you, and you made me sit through the Derek and Meredith parade, you ignored me, you humiliated me, for God's sake you had sex with that girl while your _wife_ was on the floor below you.

And then you sign our divorce papers grinning like you've never been happier in your life, you force your bright and shiny crap on me, you find out the truth and you say you never want to see me again - and now you want _another chance ?_ " she laughs hollowly. "You are unbelievable, Derek Shepherd."

The two of you stare at her for a moment, she's breathing heavily, bright hair slicked with rain and her eyes flash dangerously.

 _Red's gorgeous when she's mad_ he thinks, then snaps back to the task at hand.

"Shep,we wanted to tell you first." he entreaties.

"Tell me _what_ Mark." he snaps, he's always short tempered with him these days .

He walks to Addison's side,taking her hand in his and giving it a reassuring squeeze.

 _We're going to be all right._

" We're getting married."

* * *

 _ **Well, please review!**_


	3. Fess Up

**_So I've picked this up again._**

 ** _Sorry I've been so sluggish with this fic, Maddison are my fave but I was stuck for a lonlong long loooong time ._**

 ** _Hope you like this!_**

* * *

Derek looks like he did the time he told him he was proposing to his girlfriend at the time - blonde nurse, Camille something or other - shocked, a little skeptical, mostly horrified.

"Sorry?" he shakes his head. The man has good hair. He'll give him that.

"We're,uh." Addison gestures to herself, then to him, like she's explaining it to a toddler. "Getting married."

"Sorry." Derek says again, smiling now. "Come on, guys, I know you can do better than that, remember that one time with the nurses and the pages? That was actually funny. I can see right through you two by now - step up the game." he rolls his eyes, chuckling. "Hey, you guys want breakfast? My specialty - trout." he grins at Addison.

The guy is thicker than the Great Wall of China.

"Derek," he coughs. Addison looks like she might cry, hit him, or possibly do both.

"No trout? I thought you were less fancy than this one." he jerks his head affectionately at Addison. "You never told me why you're here."

"To tell you," Addison says, and he's pretty sure she's clenching her teeth. "We're getting married."

* * *

When she says it, _we're getting married,_ she sees the exact moment it hits him.

He drops the keys he was fumbling with, turning slowly to face them, standing haplessly on the deck, Mark's arm tight around her waist.

"You two-" he squints a little. Like he can't see them. Or just doesn't want to.

And then he laughs. Really laughs, the kind of thigh slapping, eye watering laughter she hasn't heard from him in...years, probably.

"God, you're good. You really got me." he hiccups, scooping up his keys. "Come on, I'll even make you coffee."

Okay, so it hasn't hit him yet. She used to be better at reading him.

She exchanges incredulous glances with Mark - she'd imagined yelling, ranting, maybe punching. Not...this.

Whatever this is, because Derek is still chuckling as he walks into the trailer ahead of them, talking about how he has to be at the hospital in an hour and are they coming?

"Derek," she says finally, lingering against his door. "Turn around."

"What, Addie?" he frowns, already distracted by the smelly trout he's dropped into the sink. She wonders if he's ever really changed, or if she's the the one who outgrew their marriage.

She holds up her hand, the ring sparkling dully in the sunlight that filters through tiny windows.

"The hell is that?" he squints at her hand. Trust Mark Sloan to pick the most obnoxious ring he could find. Even _Derek_ noticed it.

"Ring." Mark says helpfully, and she's reminded of herself asking the same question that morning.

But to her, it's not just a ring. It's the beginning of a new life, a fresh start, the license to be happy without the taint of guilt and regret.

* * *

It's not a just a ring. It's the end of _them_ , the death knell for any chance he may have had (not that he wanted one) , the seed of doubt that will from now on always be in his mind.

Were DerekandAddison ever real? Or was it always AddisonandMark and Derektoostupidtonotice?

"Ring...wait, you two-" he points from one face to the other, one nervous and one amused.

"Yep," Mark says. "About that coffee..."

"Shut it, Mark." he says, feeling a strange numbness creeping up his legs as he turns to Addison, who is trying to melt into the wall. "You're pregnant, aren't you."

* * *

 _"You're pregnant, aren't you."_

Well, the boy gets a point for being able to see into the past. About a year, actually.

"That's why you're doing this?" He's demanding, starting to pace in front of the sink.

He sort of wishes he'd take a minute to put that damn fish away before he starts flipping out. No wonder Addie was so pissy the whole time she lived here.

"I'm...no. I'm not." she squeaks, and he frowns. Addison Montgomery does not squeak. She yells, berates, puts down and sometimes bellows (and sometimes she screams, like she did last night...) but no, she does not squeak.

She has no reason to feel guilty now, she's done the time, she's let him hurt her back.

She doesn't have to think about his feelings now, she shouldn't be stumbling over his ego. She deserves to be happy.

"So _why,_ " Derek's saying now, gesturing like he used to in kindergarten when he got mad that he'd stolen the blue crayon. Never changes, this one.

" It wasn't a fling, Derek, you know that, it was real, we were-" she's pleading, her hands held out in the appeal he recognises too well from the last year in New York.

He gets the oddest urge to fabricate an excuse, duck out of this suffocating trailer with an apologetic smile, before he remembers this isn't a marital quarrel and he's no longer a voyeur. He's in this too.

"You know what he's like!" Derek yells.

 _Excuse me?_

"He's committed to himself, surgery, and blondes with big boobs - his words, not mine - and you want to _marry_ him? Are you insane?" Derek looks like he might laugh again.

"Married you, didn't she." he grunts, earning himself a glare from Addison and a dismissive look from Derek.

"Addison," Derek says, softly, and he feels suddenly uneasy. "Please. Think this through, I just want-"

" _You_ want? No way. Derek, what you want is no longer my concern, so please , if you can, be happy for your best friend and you used to love of your life, and if you can't, well, for once-" she leans in close, and he enjoys seeing Derek flinch a little. " _Shut. Up._ "

"And I have a surgery in forty minutes," she says, suddenly normal again. "Come on, Mark."

"You go," he says, looking at Derek's slouched form against the flimsy countertop. "I'll catch up to you."

They listen to the sounds of her car fade away, breathing in silence as rain starts to tap in earnest on the roof.

"Derek."

" _What?_ "

"You could at least look at me,"

He watches him rip a knife through the fish's guts, flecking the sink with blood.

"Or not." he mutters.

There's a very long, very silent pause where Derek disembowels his fish, he tries not to gag on the smell, and Addison texts him twice to ask what happened.

Isn't she supposed to be driving? He reminds her of this fact and tosses his phone into his pocket.

Derek may be one of the most renowned neurosurgeons in the world, a brilliant scientist and _almost_ as good looking as he is but sometimes the only way to make him see things is a good old kick up the ass. Fortunately, thirty five years of being his best friend means he is good at kicking.

"Shepherd, look at me," he says loudly, wrenching the dripping knife away from him and slamming him into the couch. (He did tell him to go to the gym more often. Of course, he doesn't listen.)

"Get out of my house," he snarls, trying to get up.

"I would, but you don't have one." he counters, and Derek concedes defeat as he looks around at his metal Twinkie house. (Nancypants never was tactful.)

"So you're going to sit there, and I'm going to talk." he orders, setting the knife down out of Derek's reach. "There's just one thing you need to do in order not to be a total dick. Butt out. She's not your business anymore. When you two were married , I ran interference, I defused your stupid fights, I never picked sides and I stood in for you while you were off making an idiot of yourself. You'll do the same for me."

He's staring at him openmouthed, looking very like the fish head eyeing him from the sink. "I-"

"Did I say you could talk?"

He shakes his head meekly.

"Good boy. Like your mom used to say - if you ain't got nothing nice to say-"

"Then don't say nothing at all." he finishes for him, and his mouth twitches. "But I was going to say something ...well, not nice, but not totally rude either."

"That'll be a refreshing change. Shoot."

"I'm not a dick."

"I beg to differ."

"Am not."

"Are too. You are a dick of epic proportions-" he stops quickly, realising what that sounded like.

Derek's eyebrows fly up into his hair. "Sloan, are you finally accepting that I -"

" _Hell_ no." he says emphatically.

"You have no proof." he smirks, regaining his composure far too quickly for Mark's liking. He's not done yet.

"We _could_ always just ask Addie," he says, and then he catches Derek's eye and they're laughing like that haven't in years, stomach-hurting, eye watering laughter that leaves them breathless and lost as to what they were laughing about in the first place.

"I missed you, Sloan." Derek gasps. "I'm sorry I was a ... dick."

" _Are._ Are a dick." he corrects, still raspy. "I'll cure you, don't worry."

"I'm not sure there _is_ a cure." Derek says soberly.

"Opinion, per rectal, three times daily."

"So you're admitting that I have..."

 ** _.._**

An hour later they've managed to stow the fish in the freezer, crack several more jokes at each others expense, and he's convinced Derek into driving him to the hospital.

"Mark," he says suddenly as they're getting out of the beat up jeep he's embarrassed by."Don't hurt her."

"Wouldn't dream of it." he says, kicking at the tyre. "But thanks. For looking out for her."

"Really?"

"It's nice to have a friend," he says carefully, not sure how thin the ice is here. "To have a friend when your husband's being a jerk."

"Yeah," Derek says softly. "Guess it is."

"We okay?" he asks as they get off the elevator on the OR floor, feeling slightly ridiculous.

Derek shoves him hard as he heads down the corridor a step ahead of him. "You're such a _woman_."

" _You're_ a woman, you-"

"You're talking to each other?" Addison gapes at them in front of the OR board. "Like, nicely?"

"We're friends," Derek says, pretending to be miffed.

"Maybe you two should get married." she snorts. "And I'll live in the trailer."

"When pigs fly." he laughs, dropping a kiss on her cheek. "Congratulations, Addie. Keep him in line."

"Thanks." she says, looking genuinely touched. "Really, Derek, you're taking it so well-"

"I wouldn't say _well_ , because that-" he points at Mark's arm sliding around her waist. "That still creeps me out. But I'll get used to it."

"You better." he grins. "I intend to do a lot of it."

Derek suppresses a shudder as Torres comes bouncing over, her eyes drawn magnetically to the ring.

"Is that what I think it is?"

* * *

 ** _Review, pretty please?_**

 ** _Next update much sooner, I promise!_**


	4. Returning Favors

**_As always, thanks for all the love on the last chapter._**

 ** _It's amazing to see Maddison so strong years after both disappeared from TV. (Thanks Shonda.)_**

* * *

"Do you have a minute?"

She's at the scrub sink when he asks for the third time, scouring under her nails with the brush. The first time , he buttonhole her in the NICU, the second time as her in a stairwell, and she's feigned emergencies each time in order to escape.

Which is something she can't really do now, since her obviously fine patient is being wheeled out of the OR after what - if he's checked the board like he always does - know is her last surgery for the day.

"Addison?"

She realises she must have zoned out a bit while she overanalysed, and turns with dripping hands to look at him. He hands her a fistful of paper towels, grinning. He knows he's got her.

"Yeah, I do." she says cautiously. _Now_ he wants to talk. Never let it be said that Derek Shepherd doesn't know how to pick his moments.

"To talk?" he cocks his head in that way she's still not sure isn't deliberate - how can he not know the effect of those damn eyes - and his hair flops just so onto his forehead .

"Okay."

* * *

She leads the way out of the scrub room, stopping to drop her paper towels in the bin, stamping her foot a little harder on the pedal than is strictly necessary. Not that it has quite the usual effect in her flat shoes she deigns to wear for surgery.

Although they _do_ make sure she has to tilt her head back a little to look him in the eye.

She walks silently to her office, closing the door behind him and gesturing briskly to the couch. Which if they were still married would mean something else entirely, and with this thought - and his knowledge of Mark's predelictions in mind - he leans against the wall instead.

She's sitting at her desk now, scrawling the op note in handwriting he knows well. She looks up at him for a moment. "Aren't you going to...talk?"

"Uh...congratulations." he says weakly, cursing himself for not having a speech prepared.

"Thank you." she replies, looking slightly confused. "Really, I wasn't expecting you to take it so well."

"I'm not." he assures her.

"Excuse me?"

That eyebrow, he knows it well. It signals the grace period wherein he can correct what he's said - or allow her to think she's misheard him - before she starts yelling.

And then usually he yells, and she stamps her feet, and he makes big gestures, and she slams doors.

"I'm not trying to hurt you," he begins earnestly. "I'm happy you're happy, but Addie-"

Okay , she's opened her mouth, she's drawn breath, he has approximately three seconds before she explodes.

"- are you? Are you really happy?"

* * *

Damn him.

And damn Callie.

And Miranda.

And Richard.

And Mark, who's calling her right now. He _never_ forgets dinner reservations.

They all asked her the same question today, and it's the one question she's never had the answer to.

Ask her about anything, fetal blood vessels and cystic fibrosis and maternal health, designer shoes, vintage wine, and she'll have the answer. She always has answers.

But this is a question she's not accustomed to being asked, and she doesn't have an answer, and it makes her feel just the slightest bit off balance.

"Yeah." she smiles. At least, she hopes it looks like a smile. "I am."

* * *

Her lips curve upwards into a smile, her eyes soft and faraway. "I am."

"He makes you happy?"

He didn't mean to sound so...incredulous. It just came out like that.

"He does," she says. "He ... notices. And he cares. He remembers things. He calls me out on things and he doesn't take excuses. And I-" she looks directly at him, appraising the situation. " I love him."

He's known her for years, he knows that she scratches her nose when she lies and shuffles her feet when she's nervous and tucks her hair behind her ears when she's guilty and stares when there's something she's not saying.

She isn't doing any of those things right now.

And the least he can do is to keep her that way.

She's actually, truly, really happy, and it shows, her eyes are sparkling and her smile is different. It's her smile from years ago, not the farce she's used in Seattle.

"That's good." he says, aware of how pathetic he sounds right now. "I'm...glad. You deserve it."

"Derek-" she reaches out across her desk to stop him leaving. "I'm sorry."

"What for?" he laughs shortly. "For being happy? Addison, don't be. We're allowed to be happy with other people, we don't have to worry about each other anymore."

"Friends worry too." she counters, perching on her desk. " And I'm worried about you."

* * *

She is worried. Because he looks pale and drawn up close, plum bruises under his eyes. His hair is slightly less than perfect today, and his eyes are bloodshot, hands shaky from caffeine and exhaustion.

"You look like crap." she says succinctly.

"Thank you, Addison. That makes me feel, I don't know. _Great_."

Oh, back to the sarcasm already. Maybe they _can_ do the mature grown up adults who are divorced and still friends thing.

"But you do." she presses. "Come on, Derek, I know all your deep dark secrets, like-"

"Shut up," he says hastily. "And you don't know _all_ my secrets."

"Yeah I do," she insists. "I know that you...miss Meredith."

He's not good at being alone, Derek. He's had four sisters and an overbearing mother, followed by college roommates, Mark and then her. And then Meredith.

"Well, she hates me." he says mournfully. If there's one thing he does better than surgery it's wallow in self pity.

But friends don't judge.

"No she doesn't." she pats him on the shoulder closest to her. She knows from personal experience that it's very hard to hate him.

Ass.

"She does," he says doggedly. "She thinks I'm going too fast."

"Going where?"

He flops a hand pointlessly in the air. "You know, kids, dog, fence."

"You wanted that?"

* * *

She looks stunned for a moment, dropping the hand resting on his shoulder.

They discussed it. _Did_ a fair bit of it, too. The brownstone had plenty of space for _maybe_. And Doc, while he was a hand-me-down from his girlfriend no less, was dog enough.

And they talked about kids, too, bickered about names and how many and _when_.

After internship would ruin her residency, after residency came fellowships, each too good to pass up. And then came Mark, and Meredith, and Seattle.

And now he's going through the same process with Meredith; he's settled, stable, but she still has things to prove.

And he's not sure he can wait.

"You know I-" he pauses. "That _we_ did. We both wanted a family. And now you have one, with Mark - or at least you have the chance, and me," he laughs bitterly. "I'm dating a twelve year old."

* * *

He's been waiting in this damn lobby for ages, trying to fend off a very persistent drug rep from a few months ago. She apparently hasn't gotten the memo yet.

But he's turning over a new leaf. For Addison.

Who is late.

He stomps his way up to her office, taking a minute to admire the sticky grey blank space after the _Montgomery_ on her door and wonders if she scraped the _Shepherd_ off with her fingernails.

Not that she'd ever risk a fingernail on something like that.

He pushes open the door to find his former best friend having a ...therapy session with his fiancé.

"Hey," he says, trying not to feel like a third wheel. Some habits are hard to break.

"Hi." she smiles, beckoning him in. "I'm so sorry I'm late-"

"You had plans?" Derek says immediately. "Sorry, man, we were just... all yours now." he grins as he ambles out into the hallway, swinging the door behind him.

"Hi." she says a little breathlessly, twining her arms around his neck.

"What's with him?" he asks, tugging at the ends of her hair where it tickles his hand. "Turning you against me?"

She smacks him in the chest. "Of course not."

She's looking at him hard now, eyes very wide. He knows that look. It's the I'm-about-to-say-something-big face.

"Addison, spill," he says firmly, helping her slide her coat over her shoulders. "Or you'll be staring at me all night and I'll go crazy thinking about what you're not saying."

"I- okay, look." she says, words tumbling out. "We've all three of us had this really weird relationship-"

 _You can say that again_.

"- I mean, even _before_ ," she emphasises the last word like it means something. Probably does, and he'll catch up in a minute.

" Before, you were like this overgrown child in our marriage, "

"Hey," he objects and she motions for him to be silent.

"And we were all friends, and Derek-" she peeks at him cautiously from under her lashes. "Derek needs a friend."

"So what you're saying is... " he struggles for a moment, wishing for a dictionary. Or a translator. Or at the very least Derek, who's probably learned a few things over the years. "You want to sleep with Derek?"

What can she possibly carry in that clanking bag that just fractured his ribs?

" _No."_ she says emphatically. "I don't. Mark, you idiot, I mean we need to be _friends_ with Derek."

"Aren't we?"

This is such a waste of time , and energy, talking about their weirdly dysfunctional threeway relationship when they could be doing-

She swats away the hand trailing up her thigh. "Friends are supposed to help each other."

He sighs as he pulls away. "What does he need? New trailer? Fishing rod?"

She rolls her eyes at him. "Remember how I used to set you up with my friends to get you out of my and Derek's faces?"

He clasp a hand over his heart, pretending to be offended. "That wasn't because they all begged you to?"

She blushes slightly, grinning. "Yeah, well, that too. My point is, I was a good friend."

"You were,"he says sincerely. "Even though none of them were exactly you."

And then they both lose the plot for a while as he kisses her, bending her back a little over the desk, until she comes up for air, flustered, and pushes him away.

"Let me finish." she says sternly, the effect somewhat lost by her mussed hair and bright eyes. "We need to set up Meredith and Derek."

"You want to play matchmaker." he says, trying not to laugh. "To McDreary and the dirty mistress."

" _You're_ a dirty mistress too." she reminds him. "And don't call him that. he's just..."

"Dreary?" he suggest while she searches for an adjective.

"You're a terrible friend." she mutters. "Fine, I'll just do it myself."

"I want to help," he protests, trailing in her wake as she moves furiously towards the door.

"Really?" she asks, hopefully, and now he's really in it because he can't resist the big blue eyes thing she's doing.

"Yup."

"Okay, so _you_ talk to Meredith. And I'll talk to Derek."

"That's your plan? Your grans plan is for me to basically talk a very screwed up girl into sleeping with my self absorbed best friend?"

"While I talk your very self absorbed best friend into sleeping with said very screwed up girl, yes." she says, locking the door behind her and taking the proffered arm as they walk towards the lobby.

"You want to be _McPimp."_ he snickers. "Addie, just in case...don't quit your day job."

"Shut up. Are you in or out?"

She's got one hand on her hip, foot tapping impatiently as she glares at him in the middle of the second floor.

"In." he says hastily, grabbing her hand before the nurses start staring. "I'm in, and now we're going to dinner."

"I knew it." she smiles in satisfaction. "Ooh, Mark. Do you think they'll get married?"

* * *

 ** _So , this is noticeably less dark and angsty than my usual stuff. I just wanted themthem to have a break, poor things._** ** _Not that it'll be all smooth sailing. But I've always liked the Mark-Addison-Derek trio, as friends, dysfunctional lovers, and as very interesting individuals. And I hated that on the show, their dynamic wasn't really explored as deeply as it could have been - years and years and years of wasted history_** ** _,plus all the moments they should have been there for each other and weren't really irks me, because med school bonds you for life whether you want it or not, and these relationships are something that can really weather a LOT_** ** _crap._**

 ** _So this will be Maddison for now, Derek, Meredith, the while circus that is Seattle Grace, and hopefully you'll stick with me to see where it goes!_**

 ** _Let me know what you think in the reviews - even if you hate it._**


	5. Sneaking Around

**_Hi!_**

 ** _I know I'm a slow updater these days - sorry, but here's another chapter._**

* * *

He's lying on his back on the couch in the attendings' lounge, one arm flung over his face, something digging into his back, waiting for them to leave.

Which they seem to be taking their sweet time doing.

"Shepherd, you're making it too easy for me," Burke teases. "There won't be any lying around on couches when _I'm_ Chief."

"Good, then it's a long way off." Mark quips, and they share a smirk behind Burke's retreating back. Addison, for some reason, looks very pleased.

"When I'm Chief, you can lie around all day." Mark is saying, helping himself to his coffee. "And you'll look good doing it."

Either Addison's neuroses have rubbed off on the man or she's put him up to this.

Why can't she just leave him alone?

"Did I mention I like the facial hair? Not too much, not-"

"What do you want, Mark?" he asks, sparing him the agony of having to come up with compliments.

"What?" he asks, looking convincingly confused. "I can't compliment my best friend?"

"I'm not your friend," he reminds him, feeling petty. Petty feels good right now, watching Addison pin an unfamiliar ring to her scrub top. "And I think we're past you having to ask me for permission for anything - you slept with my wife, after all."

"Derek." she says, turning slightly towards him so he can see half her frown.

"What? I get to remind you of it. It's my eternal right, after I walked in on you two-"

"Okay," she says hastily, slamming her locker closed. "But-"

"Shut up, Addison." he advises her. "We're not married anymore, I don't have to listen to what you say."

He feels a little bit guilty at the hurt in her eyes, but he supposes she owes him that, and then some.

So it's okay.

And it feels _good_ , to make someone else feel a little piece of what he's feeling.

* * *

Addison stalks out of the room, leaving heavy silence behind her. Derek shifts slightly on the couch, ignoring him or maybe just hoping he'll go away.

But he's not - he _can't_ \- not now that he's promised Addison he'll help her with her harebrained scheme.

Because in his extremely vast experience, making Derek Shepherd happy is a task for a saint - which neither he or Addie have ever been or will ever be - it requires monumental patience and understanding and a temper that doesn't explode at the slightest provocation.

So he recalls the words of his overpaid shrink and takes a few deep breaths before he approaches the prone figure.

"Hey Derek, I was thinking maybe we could-"

"You were _thinking_?" he says, managing to sound incredulous through his pillow. "Maybe you could have done a bit of that back when you screwed my wife in-"

"Will you shut the hell up?" he snaps back, yanking the pillow off Derek's face. "Let me say my piece, okay?"

His miserable face contorts into something resembling a smirk. "Addison put you up to this, didn't she?"

"What?" he stumbles, cursing himself for being so obvious. Or maybe it's just that Derek knows him so well. Knows _both_ of them so well. "No. No, of course not."

"What did she threaten you with?" he grins lazily, stretching his arms. "Wait- I don't want to hear it. Maybe she'll kill you and get arrested and I'll be shot of the both of you."

* * *

"Dr. Grey," she says pleasantly. It might have come out a little high pitched, though, judging by the way Karev is looking at her.

"Dr. Montgomery." she says, looking mildly curious.

"Sloan," Karev grins, gesturing to the ring pinned to her top. "Congratulations, . On your...engagement. And winning you be-"

"Thank you, Karev." she says before the whole scrub room has to hear about the sex bet.

"How's your blood pressure?" he whispers as they're scrubbing in next to each other, and she can feel her cheeks turn traitorous pink.

"It's fine, thank you." she replies curtly.

"Are you not feeling well?" Grey asks, sounding concerned. "Should I get someone to cover for you?"

"No!" she yelps, almost brushing a hand against the wall. "I mean, no, I'm fine, I -"

She stops short when she sees Karev walk through the glass doors quaking with silent laughter.

"Believe me, she's fine." he calls over his shoulder as he slides his arms into a gown.

"I'm fine." she assures Meredith, who by now just looks tired. "Let's go."

* * *

"You're a horrible person." he says bluntly. "Like, really awful. As bad as Archer."

"Hey," Derek protests. "I don't sleep with everything that has a double X chromosome. Unlike Archer and you."

There's a pause where Derek's mouth hangs open and he waits for him to close it so he can punch him without dislocating his jaw.

That would be nice, though.

But then he says "Not anymore, I guess."

"Not anymore." he agrees.

"Mark Sloan, manwhore extraordinaire," he sighs. "Engaged. To my wife."

"Ex-wife." he reminds him, wondering if they'll always be this intertwined. Not that he's sure he'd want it any other way.

"Ex." he agrees, sitting up and reclaiming his pillow. "But not...ex- friend?"

"Not unless you want it to be."

"I don't." he says heavily, and knowing him, it probably took a week's reserve of courage to say it.

"So we're not exes," he says.

"No."

"Good." he says carefully,wondering where they go from here. He should have let Addison handle this part, she's better with emotions and stuff like that.

"Good." Derek echoes.

"Yeah."

* * *

"Clamp." she says as coolly as she can while blood is spattering her front, and it's instantly in her hand.

"The vessels are really friable," Meredith says tentatively as she starts ligating, staring at the massively ugly tumor they've spent the last three hours with. "Should we be-"

"I definitely should," she says, looking at Meredith over her mask. "You're free to decide for yourself."

She cuts her eyes to Karev, semi-attentive in front of the fetal monitor. "What about you, Karev, got somewhere else you'd rather be?"

" _I_ don't." he says in a tone that suggests that _she_ might.

This one really needs to be taken down a peg or three, but she'll launch that campaign after she's gotten Derek back with his little intern.

Although said intern looks fairly droopy right now, clutching a suction tube, eyes bleary.

Derek has that effect on people.

Although when he tries, he can really-

Surgery. Long difficult but pretty routine surgery, she reminds herself.

A lot is hinging on this surgery going well- the patients life, mostly, but also phase two of her plan.

She thought they could call it Operation MerDer, but Mark laughed so hard he almost fell off the bed.

He _did_ make it up to her though.

"I'm getting decels." Karev says.

"What's the lower limit for a fetal heart rate?" she asks, looking at Meredith.

"She's at 20 weeks, which means... 140?"

* * *

"Are you asking me?" she says silkily, giving Meredith that piercing look he's been on the receiving end of way too many times now.

"140." she says more firmly and Montgomery looks appeased.

"I'm almost done here anyway," she's saying now, eyeing the scans on the lightboard, making sure she's got clean margins. "Meredith, how would you like to close?"

" _Me?_ "

"Unless Karev has changed his name to Meredith, then yes, you."

* * *

She thought this girl had fire, a little something that made Derek pick her. Now...well, now she's just a soggy mess.

Damn Derek.

"Go ahead," she says, more gently this time. "I'm right here if you need me."

"Can I do it?" Karev asks, rising from his stool like an eager little puppy.

She pins him back down with a glare. She trying to get _Meredith_ with Derek - her ex husband might have changed a lot in the past year, but she's pretty sure Karev still isn't his type.

"O-kay," Grey is saying. "5-0 prolene please."

She's got good hands, she notes. Steady, even if the rest of her isn't.

She'll be a good surgeon. Maybe she should call off the plan...

* * *

"I'm...glad we're friends." he says. God, he sounds lame.

The things he does for Addison...

"Mark?"

"Yeah?"

"Can we please be normal?"

"Yeah," he says, relief flooding his body. "I was just saying, maybe we could go out, get a drink, like we used to?"

"Joe's?"

"At eight."

"Mark..."

What now.

"..you're happy, right?" He's asking. "With her. She makes you happy."

"She does," he says slowly, not sure if it's okay to discuss this yet. But she him happy, like, sick dizzy walking-on-clouds happy.

Like he has everything he's ever wanted, like nothing can ever touch this feeling.

"Don't...hurt her.".Derek says softly, rising to his feet. "And don't let her get away with shit."

"Wouldn't dream of it."

Derek actually smiles as he walks away. Maybe Addison was right after all.

* * *

"Done!" Meredith says, sounding surprised.

"And well done." she smiles even though she won't see it.

She can feel Karev staring at her, and she studiously ignores him as they scrub out, Meredith babbling incessantly, some sparkle back in her eyes.

"Why'd you do that?" he asks, almost civil, as Meredith bounds ahead of them.

"What?" she asks, trying to sound innocent.

"Y'know," he mumbles, suddenly shy. " _That_."

He jerks a thumb at Meredith, who positively beaming as she reaches for the patient's chart.

"I figured she needed a little... reaffirmation." she shrugs, relieved that her plan seems to be working.

"Yeah," he says fervently. "Thanks."

"You're...welcome."

Huh. Polite Karev. She must remember to check the moon tonight- she has a feeling it might be blue.

"Thanks." Meredith says a little huskily, shuffling her feet. "For letting me..."

"No problem," she replies breezily. "And as congratulations for the best sutures I've seen from an intern in a while... how about I buy you a drink tonight?"

"It seems to be what everyone around here does when they're happy," she explains, feeling a little foolish at the look on the younger woman's face.

"Also when they're sad," she says finally, relaxing into a smile that makes her pale eyes warm up a bit. "Or mad, or-"

"All the time, really." she finishes, smiling. "Joe's at eight fine with you?"

"Yup."

"It's fine with me too," Karev whispers so only she can hear and she refrains from stepping on his toes with great difficulty.

Her phone buzzes against her hip and she opens it to find a text from Mark.

 ** _Mission accomplished_**

She smiles a little- the line was her idea, too.

She texts him back to say she'll be there at eight too.

Now all she needs is for Derek to not be an ass, and her project will be well on its way to success.

* * *

 ** _I promise I'll be updating my WIPs - especially WWCHB - pretty soon. Thanks for all the sweet reviews you guys keep leaving on them, it makes me realise you haven't lost interest. I haven't either!_**

 ** _This story is going to be pretty lighthearted, no tears or soul crushing confessions or angsty drawn out reunions like my other stuff._**

 ** _And it's sort of funny how you're another worried I'll kill one - or possibly all - of our babies._** ** _I'll try not to._**

 ** _Mwahaha._**

 ** _Just kidding._**

 ** _Mostly._**

 ** _Review please? They're always worth the wait - see what I did there - but reviewing RIGHT AWAY makes me update reallllyyy fast._**

 ** _And also, for those still in doubt : THIS IS A MADDISON FIC THAT HAS MERDER MIXED INTO IT._** ** _I REPEAT, THERE IS A SUBSTANTIAL AMOUNT OF MERDER. AND CONSIDERABLY MORE MADDISON CAUSE I'M WEIRD LIKE THAT._**

 ** _Thank you._** ** _And now go review, you can do it in shouty capitals if you want. And feel free to leave me some suggestions as to what you want to see re:MerDer in this story; I'm a bit new to these two so I don't know what you might like._**

 ** _Not that I always do what you like._**

 ** _Annnd... this has been a shamefully long A/N I know about half of you will not read_** ** _._**

 ** _I_** ** _love you anyway._**


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